Tumbleweed Whenever you think of the Wild West of America, you think of cowboy movies and tumbleweed, perpetually tumbling around a desolate landscape.
Salt lowers the freezing/melting point of water, so in both cases the idea is to take advantage of the lower melting point. Ice forms when theÂ­ temperature of water reaches 32 degrees Fahrenheit (0 degrees Celsius). When you add salt, that temperature drops: A 10-percent salt solution freezes at 20 F (-6 C), and a 20-percent solution freezes at 2 F (-16 C). On a roadway, this means that if you sprinkle salt on the ice, you can melt it. The salt dissolves into the liquid water in the ice and lowers its freezing point.
For a solution of table salt (sodium chloride, NaCl) in water, this temperature is -21Â°C (-6Â°F) under controlled lab conditions. In the real world, on a real sidewalk, sodium chloride can melt ice only down to about -9Â°C (15Â°F).Colligative Properties. Freezing point depression is a colligative property of water.hen you add a salt to ice with a little bit of water, the salt lowers the freezing point of the water, keeping it from re-freezing as easily and helping to melt the rest of the ice. Thomas Northcut, Getty Images.